title: Evaluation of toxicity and oxidative stress induced by copper oxide nanoparticles in the green alga Chlamydomonas reinhardtii.
abstract: Copper oxide nanoparticles (CuO NP) are frequently employed for their antimicrobial properties in antifouling paints. Their extensive use can contaminate aquatic ecosystems. However, the toxicological effects of this NP in the environment are poorly known. In this study, we evaluated the toxicity and oxidative stress induced by CuO NP on Chlamydomonas reinhardtii using several toxicological assays. CuO NP was found to induce growth inhibition and a significant decrease in carotenoids levels. From data on cells density after 72 h of CuO NP exposure in light, the EC50 value was calculated to be 150.45±1.17 mg L(-1) and the NOEC≤100 mg L(-1). Evaluation of esterase activity demonstrates a decrease in cell metabolism activity with the increase of CuO NP concentration. The CuO NP induced an increase of reactive species level (190±0.45% at 1000 mg L(-1) after 72 h of exposition, compared to control) and lipid peroxidation of cellular membranes (73±2% at 1000 mg L(-1) of CuO NP in 72 h of exposition, compared to control). Investigation of CuO NP uptake showed the presence of NP into C. reinhardtii cells in different sites of the cell and, biomarkers of enzymatic antioxidants showed a change of activity after CuO NP exposition. In conclusion, C. reinhardtii was shown to be sensitive to the presence of CuO NP in their environment and CuO NP treatments induced a toxic response from 0.1 mg L(-1) after 72 h of treatment.
authors.affiliation: Laboratory of Environmental Toxicology, LABTOX, Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Campus Trindade, Florianopolis, SC, CEP 88040-970, Brazil; Department of Chemistry, University of Quebec in Montreal, C.P. 8888, Succ. Centre-Ville, Montreal, Quebec, H3C 3P8, Canada.
authors.forename: Silvia Pedroso
authors.initials: SP
authors.lastname: Melegari
authors.forename: François
authors.initials: F
authors.lastname: Perreault
authors.forename: Rejane Helena Ribeiro
authors.initials: RH
authors.lastname: Costa
authors.forename: Radovan
authors.initials: R
authors.lastname: Popovic
authors.forename: William Gerson
authors.initials: WG
authors.lastname: Matias
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002338:Carotenoids / Q000032:analysis; D002470:Cell Survival / Q000187:drug effects; D016825:Chlamydomonas reinhardtii / Q000187:drug effects* / Q000648:ultrastructure; D002734:Chlorophyll / Q000032:analysis; D003300:Copper / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D004798:Enzymes / Q000378:metabolism; D053768:Metal Nanoparticles / Q000633:toxicity*; D046529:Microscopy, Electron, Transmission; D018384:Oxidative Stress / Q000187:drug effects*
chemical_list: D015415:Biomarkers; D004798:Enzymes; D002734:Chlorophyll; D002338:Carotenoids; D003300:Copper; C000520:cuprous oxide
keywords: Antioxidants enzymes activity; Chlamydomonas reinhardtii; Copper oxide nanoparticles; Lipid peroxidation; Reactive oxygen species